This disclosure pertains to quantum dots, and particularly to a countermeasure system for protecting an asset from a missile attack using quantum dots and a method of simulating a radiation signature of an asset using quantum dots.
Assets such as satellites can be vulnerable to a missile attack. Hence, the need to protect such assets. Generally, missiles use various methods to track and seek their target. For example, missiles can seek the target by sensing the radiation (e.g., infrared) signature of the target such as the radiation emanating from the target (e.g., the heat of the target's engine).
Various methods for protecting such assets exist. For example, conventional deployable infrared (IR) countermeasures use pyrolytic materials, such as magnesium-viton-teflon (MVT), in the form of flares, to generate an intense blackbody signature by utilizing a highly exothermic reaction. The radiation emitted by the exothermic reaction peaks in the short, wavelength infrared (SWIR) range between about 1 μm and about 3 μm. The exothermic reaction serves to simulate or imitate the heat signature of the asset (e.g., heat from the blackbody emission of the satellite), thus fooling the heat seeking missile to target the origin of the exothermic reaction instead of the asset. This is considered the simplest form of active IR countermeasure (CM). Other mechanisms, such as pulse generators and lasers have also been used in trying to trick radiation seekers.
However, active countermeasures have numerous limitations in the space domain, due to target velocity, the extreme (between about 100 km and about 1000 km) standoff range of the asset and the anaerobic environment, which restricts the use of certain systems which rely upon oxygen to feed the exothermic reaction. Passive countermeasures also exist. However, passive countermeasures lack the ability to precisely replicate the spectral signature of the target.
Current countermeasure systems are inadequate to the task of spoofing an IR seeker's intent on targeting a near ambient temperature (e.g., about 300° K) target such as a spacecraft, which can have peak blackbody radiation intensities well into the long wavelength infrared (LWIR) range between about 8 μm and about 12 μm. Indeed, numerous methods exist for discriminating the targeted asset from current decoy technology. For example, an LWIR sensor is able to easily differentiate the targeted asset which emits radiation with peak intensities in the LWIR range from the decoy because the relatively small surface area decoy has a peak intensity outside of the LWIR band. Indeed, the decoy emits in the mid-wavelength infrared (MWIR) or short wavelength infrared (SWIR) ranges outside the long wavelength infrared (LWIR) range. Furthermore, the difference in intensity peaks between the radiation emitted by the decoy and the radiation emitted by the target can be used to differentiate between the decoy and the target by employing a two color sensor in the IR.
Countermeasures against intercontinental ballistic missiles (ICBMs) and intermediate-range ballistic missiles (IRBMs) have utilized inflatable balloons to try to spoof radar and IR seeker systems. Such balloons can be inflated to a size roughly comparable to that of the target they intend to protect. However, from an orbital standpoint, inflatable balloons may create a significant debris hazard, particularly if they are punctured by errant debris or otherwise if destroyed by the missile. Therefore, in general, existing countermeasures have had certain limitations.